Kainate reduces two voltage-dependent potassium conductances in rat hippocampal neurons in vitro.

The mechanisms of action of kainate were studied in CA1 hippocampal neurons using the single electrode voltage-clamp technique in vitro. Kainate (100-200 nM) reduced the potassium current which is responsible for the anomalous rectification (IQ). In 30% of the cells the drug reduced the calcium-dependent potassium current (IC) which is responsible for the afterhyperpolarization that follows calcium action potentials. The reduction of IC will contribute to the enhancement of the neural excitability by this drug.